From what I can find, SES means Small Edison Screw, a European standard base? I'm not sure if they are the same but check out Bulbman.com. They have bulbs with what they call a European base, that might work. You should email an inquiry to them.
i finally found them at B&H, it is for a patterson safelight 760, and i am super surprised no where carries these bulbs, but it is what it is.
